Preparation method of TAP-BTCA-COF / viscose composite spunlaced non-woven fabric for dye adsorption

Abstract

The invention discloses a preparation method of a TAP-BTCA-COF / viscose composite spunlaced non-woven fabric for dye adsorption, which comprises the following steps: taking a viscose spunlaced non-woven fabric as a base fabric, taking 1, 3, 5-tris (4-aminophenyl) benzene and 1, 3, 5-benzenetricarboxaldehyde as organic ligands, and adopting a one-step in-situ solvothermal method to prepare the TAP-BTCA-COF / viscose composite spunlaced non-woven fabric. The TAP-BTCA-COF adhesive composite spunlaced non-woven fabric prepared by the invention can efficiently adsorb organic dyes in printing and dyeing wastewater, has the characteristics of easily available raw materials, simple preparation method, recyclability, cyclic utilization, environmental protection and economy, and has a good application prospect in the field of printing and dyeing wastewater treatment.

Description

Technical Field

[0001] This invention belongs to the field of functional modification of nonwoven fabrics using covalent organic framework materials (COFs), and specifically relates to a method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption. Background Technology

[0002] The rapid development of global industrialization has exacerbated pollution from industrial wastewater and urban sewage. Dyeing and printing wastewater contains large amounts of organic dyes. These dyes, due to their strong chemical stability and resistance to photolysis and oxidation, remain in water bodies for extended periods, causing persistent color pollution and hindering light transmission, severely disrupting aquatic ecosystems and impacting human health. Adsorption is one of the most commonly used methods for treating dye wastewater, offering advantages such as high efficiency, ease of operation, and wide applicability. Covalent organic frameworks (COFs) are a new type of crystalline organic porous two- or three-dimensional material, composed of organic building blocks connected by strong covalent bonds. They possess characteristics such as high specific surface area, adjustable pore size, and excellent chemical and thermal stability. Currently, they are widely used in adsorption and separation, catalysis, sensing, and energy storage. TAP-BTCA-COF is an imino-COF with excellent water stability. Its structure maintains good stability for months when immersed in various organic solvents at room temperature. Its mesoporous properties and large porous windows allow reactant molecules, such as organic dyes, to easily approach the active site, making it an ideal material for dye adsorption in wastewater. However, powdered COF is difficult to recover and reuse after dye adsorption. Viscose spunlace nonwoven fabric has abundant raw material sources, a clean production process, and high yield. Furthermore, its macromolecular chain side groups contain active hydroxyl groups, making it easy to functionalize and modify. A simple one-step in-situ growth method can be used to immobilize TAP-BTCA-COF on a continuous carrier viscose spunlace nonwoven fabric to prepare a composite adsorbent material. This method not only combines the advantages of both materials to prepare a highly efficient dye adsorbent material but also enables material recycling. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption. Addressing the shortcomings of existing technologies, this invention employs a one-step in-situ solvothermal method to synthesize TAP-BTCA-COF / viscose composite spunlace nonwoven fabric. The viscose spunlace nonwoven fabric and the raw materials for synthesizing TAP-BTCA-COF are added together into a reaction vessel, thus obtaining the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric in one step. The entire preparation process is simple, low-cost, requires minimal experimental conditions, is easily industrialized, and exhibits excellent cyclic adsorption performance, making it environmentally friendly and energy-saving.

[0004] To solve the above technical problems, the following technical solution is adopted:

[0005] A method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption, characterized by comprising the following steps:

[0006] (1) Preparation of the reaction solution:

[0007] A certain amount of 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzyltriformaldehyde were added to an acetonitrile solution, and then sonicated until the additives were completely dissolved.

[0008] (2) Preparation of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric:

[0009] The viscose spunlace nonwoven fabric was pre-impregnated in the reaction solution, then acetic acid was added, and the mixture was magnetically stirred and sealed for reaction at room temperature. After the reaction was completed, the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was obtained by washing and drying.

[0010] After optimization, the viscose hydroentangled nonwoven fabric needs to be washed before use: first, the viscose hydroentangled nonwoven fabric is soaked and washed with anhydrous ethanol, then washed with deionized water, and air-dried at room temperature.

[0011] After optimization, in step (1), the ultrasonic dissolution time is 10-20 min.

[0012] After optimization, in step (1), the feeding ratio of 1,3,5-tris(4-aminophenyl)benzene, 1,3,5-benzenetriformaldehyde and acetonitrile is 7.05-28.2:3.25-13:3-7, with units of mg:mg:mL.

[0013] After optimization, in step (2), the viscose hydroentangled nonwoven fabric is pre-impregnated in the reaction solution for 10 minutes.

[0014] After optimization, the reaction time in step (2) is 24 hours.

[0015] After optimization, step (2) involves alternating washing with acetonitrile and ethanol.

[0016] After selection, wash alternately 3 times.

[0017] After optimization, in step (2), after washing, the product is dried in a vacuum drying oven.

[0018] After optimization, the vacuum drying temperature is 50℃ and the vacuum drying time is 12h.

[0019] The above technical solution has the following beneficial effects:

[0020] The TAP-BTCA-COF / viscose composite spunlace nonwoven fabric prepared in this invention is effective for the adsorption and removal of common acidic or alkaline organic dyes in dyeing and printing wastewater. Among them, the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric exhibits the best adsorption efficiency for Congo red (CR) dye in water. Furthermore, the adsorbed dye can be recycled and reused multiple times, offering advantages such as simple preparation method, ease of industrialization, and environmental friendliness and energy saving. Characterization results demonstrate that this adsorbent material has high organic dye removal efficiency, good reusability and structural stability, and strong adaptability, showing broad application prospects in the field of wastewater treatment. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings:

[0022] Figure 1 Scanning electron microscope image of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric;

[0023] Figure 2 The adsorption efficiency curves of different dyes on TAP-BTCA-COF / viscose composite spunlace nonwoven fabric are shown.

[0024] Figure 3 The adsorption efficiency curves of CR on TAP-BTCA-COF / viscose composite spunlace nonwoven fabrics under different initial dye liquor concentrations are shown.

[0025] Figure 4 The adsorption efficiency curves of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR under different pH values ​​of the adsorption solution are shown.

[0026] Figure 5 The adsorption efficiency curves of CR on TAP-BTCA-COF / viscose composite spunlace nonwoven fabric at different adsorption temperatures are shown.

[0027] Figure 6 The graph shows the adsorption efficiency of CR after 5 cycles of adsorption on TAP-BTCA-COF / viscose composite spunlace nonwoven fabric. Detailed Implementation

[0028] This invention aims to provide a method for preparing TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption. The method employs a solvothermal one-step in-situ synthesis of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric. The viscose spunlace nonwoven fabric and the raw materials for synthesizing TAP-BTCA-COF are added together into a reaction vessel to obtain the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric in one step. The entire preparation process is simple, low-cost, requires minimal experimental conditions, is easily industrialized, and exhibits excellent cyclic adsorption performance, making it environmentally friendly and energy-saving.

[0029] The present invention will be described in detail below with reference to specific embodiments:

[0030] Take a certain amount of viscose hydroentangled nonwoven fabric (2*2cm) 2 The product was washed with ethanol and deionized water and air-dried at room temperature. Separately, 14.1 mg of 1,3,5-tris(4-aminophenyl)benzene and 6.5 mg of 1,3,5-benzenetriformaldehyde were completely dissolved in 5 mL of acetonitrile solution to obtain a reaction solution. The treated viscose hydrospunlace nonwoven fabric was then immersed in the reaction solution for 10 min. 700 mL of acetic acid was added to the reaction solution, and the mixture was stirred thoroughly at room temperature and reacted for 24 h at room temperature. After the reaction was complete, the fabric was washed three times alternately with acetonitrile and ethanol, and then vacuum-dried at 50 °C for 12 h to obtain the TAP-BTCA-COF / viscose composite hydrospunlace nonwoven fabric.

[0031] The surface morphology of the prepared TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was observed using a JSM-5610LV scanning electron microscope as follows: Figure 1 As can be seen from the figure, the TAP-BTCA-COF grown on the fiber surface of the viscose hydroentangled nonwoven fabric has a regular spherical structure, is uniformly distributed, and has a particle size of about 200 nm.

[0032] Weigh a certain amount of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric, place it in a beaker, add 50 mL of CR aqueous solution with a concentration of 20 mg / L, stir and adsorb in a water bath at 25 °C, take a certain amount of supernatant at a certain time interval, test its absorbance with a TU-1901 UV-Vis spectrophotometer, and calculate its adsorption efficiency according to the following formula (1).

[0033]

[0034] In addition, aqueous solutions of different dyes, namely methylene blue (MB), rhodamine B (RhB) and methyl orange (MO), were prepared. 50 mL of the above dye solutions were placed in a water bath. Then, a certain amount of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was weighed and placed in the beaker. The fabric was stirred and adsorbed in a water bath at 25°C. A certain amount of supernatant was taken at certain time intervals, and its absorbance was tested using a TU-1901 UV-Vis spectrophotometer. The adsorption efficiency was calculated according to formula (1). The adsorption efficiency curves of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for different organic dyes are shown below. Figure 2 As shown in the figure, the adsorption efficiency of this composite spunlace nonwoven fabric for both CR and RhB can reach over 95%, with the best adsorption efficiency for CR, while it also has a certain adsorption efficiency for MB and MO.

[0035] CR dye solutions with initial concentrations of 20, 30, 40, 50, and 60 mg / L were prepared respectively. 50 mL of each of these CR aqueous solutions with different initial concentrations was taken, and a certain amount of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was added. The fabric was then stirred and adsorbed in a water bath at 25°C. A certain amount of supernatant was taken at certain time intervals, and its absorbance was measured using a TU-1901 UV-Vis spectrophotometer. The adsorption efficiency was calculated according to formula (1). The adsorption efficiency curves of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR at different initial dye concentrations are shown below. Figure 3 As shown in the figure, the adsorption efficiency gradually decreases with increasing initial dye concentration. At an initial dye concentration of 20 mg / L, the adsorption of CR in water by the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric reaches equilibrium within 60 minutes, at which point the adsorption efficiency is highest at 99.35%. This is likely because at low CR solution concentrations, the adsorbent material surface has sufficient active sites to rapidly adsorb CR molecules from the solution. As the CR solution concentration increases, the active sites are gradually occupied by CR molecules during adsorption, leading to the adsorbent gradually reaching saturation and becoming unable to effectively adsorb the remaining dye molecules in the solution, thus reducing the adsorption efficiency.

[0036] CR aqueous solutions with a concentration of 20 mg / L were prepared at pH values ​​of 3, 5, 7, 9 and 11 respectively. 50 mL of the dye solution at different pH values ​​was taken, and a certain amount of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was added. The fabric was placed in a water bath at 25℃ and stirred for adsorption. A certain amount of supernatant was taken at certain time intervals, and its absorbance was measured using a TU-1901 UV-Vis spectrophotometer. The adsorption efficiency was calculated according to formula (1). The adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR at different pH values ​​is as follows: Figure 4 As shown in the figure, the adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR is optimal at a neutral pH, reaching approximately 99.35% after equilibration within 60 minutes. This is attributed to the reduced deprotonation of the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric under acidic conditions, which weakens the electrostatic interaction with CR molecules, leading to a decrease in adsorption efficiency. When the pH of the adsorption solution is higher (pH = 9 and 11), the adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR also decreases, and the adsorption equilibrium time is prolonged. This is because with increasing pH, the number of negatively charged sites on the surface of the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric increases; while under strongly alkaline conditions, the negative charge of CR leads to enhanced electrostatic repulsion, thus reducing adsorption performance.

[0037] A certain amount of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was weighed and placed in a beaker. 50 mL of CR aqueous solution with a concentration of 20 mg / L was added. The beaker was then placed in water baths at different temperatures (25℃, 35℃, 45℃ and 55℃) and stirred for adsorption. A certain amount of supernatant was taken at certain time intervals, and its absorbance was measured using a TU-1901 UV-Vis spectrophotometer. The adsorption efficiency was calculated according to formula (1). The adsorption efficiency curves of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR at different adsorption temperatures are shown below. Figure 5 As shown in the figure, the adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR increases with increasing adsorption temperature. The adsorption efficiency reaches its maximum, approximately 99%, at adsorption temperatures of 45℃ and 55℃, with an adsorption equilibrium time of 60 min. Since the adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for water CR is very close at adsorption temperatures of 45℃ and 55℃, and considering that higher adsorption temperatures lead to higher energy consumption and cause some damage to the morphology of the adsorbent material, the optimal adsorption temperature during the adsorption process is 45℃.

[0038] Anhydrous ethanol was used as the desorbent. The TAP-BTCA-COF / viscose composite spunlace nonwoven fabric, which had already adsorbed CR, was washed three times with anhydrous ethanol, then immersed in 50 ml of anhydrous ethanol until desorption was complete. After drying in a vacuum oven at 50°C, the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was used as the adsorbent to adsorb CR from the water. The absorbance was measured using a TU-1901 UV-Vis spectrophotometer. This adsorption-desorption cycle was repeated five times. The reusable adsorption efficiency results are as follows: Figure 6 As shown in the figure, after five adsorption-desorption cycles, the adsorption efficiency of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for CR remains above 60%, indicating that TAP-BTCA-COF / viscose composite spunlace nonwoven fabric has good reusability.

[0039] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption, characterized in that... Includes the following steps: (1) Preparation of the reaction solution: A certain amount of 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzyltriformaldehyde were added to an acetonitrile solution, and then sonicated until the additives were completely dissolved. (2) Preparation of TAP-BTCA-COF / viscose composite spunlace nonwoven fabric: The viscose spunlace nonwoven fabric was pre-impregnated in the reaction solution, then acetic acid was added, and the mixture was magnetically stirred and sealed for reaction at room temperature. After the reaction was completed, the TAP-BTCA-COF / viscose composite spunlace nonwoven fabric was obtained by washing and drying.

2. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: The viscose spunlace nonwoven fabric needs to be washed before use: first, the viscose spunlace nonwoven fabric is soaked in anhydrous ethanol and washed, then washed with deionized water and air-dried at room temperature.

3. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: In step (1), the ultrasonic dissolution time is 10–20 min.

4. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: In step (1), the feeding ratio of 1,3,5-tris(4-aminophenyl)benzene, 1,3,5-benzenetriformaldehyde and acetonitrile is 7.05-28.2:3.25-13:3-7, with units of mg:mg:mL.

5. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: In step (2), the viscose hydroentangled nonwoven fabric is pre-impregnated in the reaction solution for 10 minutes.

6. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: The reaction time for step (2) is 24 hours.

7. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: In step (2), acetonitrile and ethanol are used for alternating washing.

8. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 7, characterized in that: Wash three times alternately.

9. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 1, characterized in that: In step (2), after washing, the product is dried in a vacuum drying oven.

10. The method for preparing a TAP-BTCA-COF / viscose composite spunlace nonwoven fabric for dye adsorption according to claim 9, characterized in that: The vacuum drying temperature is 50℃, and the vacuum drying time is 12h.

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